For example, FOXO3 expression is regulated by its DNA methylation status in mouse embryonic fibroblasts31 and hypomethylating agents including Azacytidine and Decitabine can restore FOXO3 in acute myeloid leukaemia patients.32FOXO3 has also been identified as one of the target genes regulated by EZH2-H3K27me3-dependent transcriptional network in hepatocellular carcinoma.33 On the contrary, FOXO3 has also been reported to be a transcriptional regulator of DNMT3b in lung cancer.34 This evidence concerns the gene FOXO3 and lung cancer.